I disagree with Chris in that you don't just want to shorten the cable. It's not the length of cable I'm worried about, but that tiny connector you don't want to replicate. The connector and the wires immediately coming out of it look to be intact. Replacing that will be a major pain in the butt, so I'd go to reasonable length to preserve that piece.
Since that piece is now short, you'll have to make a splice. Just realize up front you're not going to make a splice in such small cable that is anything like the size of the cable. The splice will be big, fat, and ugly in comparison. It looks like it can be made to serve as the strain relief too, so that helps a little.
To splice such tiny wires, see if you can sortof stick the stranded ends into each other. That may take some persuasion under a magnifying light, and then some weighty objects on your bench to hold them in place while you solder. This won't be easy, but it should be doable. If that just isn't practical, give up and bend each wire into a U and hook the two U ends together, flatten them together with a needlenose, then solder.
Once you have the connections made, wrap each one individually in a small piece of electrical tape, then wrap the whole bundle in electrical tape so that is looks like one fat section of cable. Like I said, big, fat, and ugly, but it should work. All that tape will act like a strain relief, so that section shouldn't break again.
I haven't tested it buy my gut feeling is the breakdown of hotglue will be below 5kV
Some high voltage electric tapes are rated up to ~70kV, make sure there is a continuous wrap that is clean as any residue on the tape could conduct. Any residue on the outside of the wire could also conduct.
The best way would be to get some high voltage wire that has a breakdown above that of the voltage you are experimenting with.
Best Answer
According to this selection guide, you should pick a tubing size which is
~20-30%larger than the thickest diameter object which the heat shrink will cover. Additionally, you want the minimum reduction ID to be smaller than the minimum diameter object so you'll get a snug/tight fit.I'm assuming this is the tubing datasheet you're interested in: FIT-221B-3/16
I was not able to find the wire in question, but let's assume that your statement about a
0.145"diameter for the wire + insulation was accurate.The tubing has a minimum expanded diameter of
0.187", which is ~29%larger than the wire (including insulation).The maximum recovery ID is
0.093", which is more than enough to securely cover the insulated portions of the wire (0.93" < 0.145").There are still one outstanding questions to answer:
Presumably you actually want to solder the wire to something (in your case, an LED). This means there will be portions of the wire without insulation, and there will be some lead thickness which needs to be taken into account.
Let's take for example this red LED. It has square leads with a maximum side length of
0.525mm, or0.0207".Suppose the wire thickness was 8 AWG, 0.145" total thickness (quite thick insulation). Then the cross-sectional profile looks something like this:
Ignoring the solder, the thickness of the wire and the LED lead is:
\begin{equation} \sqrt{(\frac{0.1285 in.}{2} + 0.0207 in.)^2 + (0.0207 in.)^2} + \frac{0.1285 in.}{2} = 0.1517 in. \end{equation}
This is still ~23% smaller than the tube expanded ID, so we're good here. Likewise, the minimum recovery ID checks out too because the wire itself is larger. Adding on solder might make it a bit tight of a fit, but it should still fit (just don't glob on too much solder).
Now on the other end of the spectrum, suppose we have a 22 AWG, 0.145" total thickness (quite thin insulation). This time the cross-sectional area looks like:
And the minimum diameter is now
0.046". This time, we will have problems because the reduced heat shrink won't tightly wrap around the section containing the wire and the LED lead. In this case, we would need shrink tubing with a shrinkage ratio of 4:1.So in conclusion (tl;dr): It might work, but you'll need to know more about the wire dimensions, as well as what you're attaching the wire to. For the 22 AWG case you'll need a much higher shrinkage ratio to tightly wrap the actual joint. For a thicker wire, say 8 AWG the proposed tubing should be fine. There could be other factors as well such as heat shrink tubing material properties, but I doubt for the majority of projects these are a major concern.